1. Field of Invention
This invention relates to the field of object oriented application and operating systems development, and more particularly, to methods and systems for performing administrative operations on object oriented applications operating in a distributed object programming environment.
2. Background of Invention
Client-server computing is the predominant model for the management of computing resources, typically on a network of distributed computers. Servers are computers and application programs executing thereon that provide various functional operations and data, upon request. Clients are computers and applications that request such services. While clients and servers may be distributed in various computers on a network, they may also reside in a single computer, with individual applications providing client or server functions, or both.
In a client-server system based on a object oriented development environment, a client is code that invokes or manipulates an object, and the object that is invoked is the server. A server provides a number of interfaces to clients for invoking various objects within the server that provide functionality requested by a client. Each of the objects may have multiple implementations, or object code that executes the functionality of the code when an instance of the object is created by the server. Thus, a particular interface, when used by a client to invoke an object, will result in the execution of a particular implementation for the object that is invoked. When the server or one of its objects is invoked, the server will operate in accordance with certain configuration information, such as the location of its data directory, the executable pathname, and the like. In a client-server system, it is desirable to be able to determine and manipulate the configuration information for a server available on the network without consuming system resources by invoking the server.
Information about a server can be classified into two categories. Dynamic information arises out of a particular process that is executing a server, such as its process identifier, how many objects are active within the server, and the like. This information is dynamic because it depends on a current executing process which is transient. Static information is information that does not devolve from a particular execution or process. This includes external information such as the identify of the host computer of where the server is installed, its pathname, its execution definition, and internal information, such as the identity and description of the object interfaces and implementations the server provides, and the setup of various application programming interfaces used by the server, such as the identity and configuration of tracing facilities available in the server, log file configurations, and reaping functions.
Conventionally, systems administrators have various software tools for determining the configuration and related information about servers on various computers on a network. However, these administrative tools require that the server be executing as a process for any information to be obtained, and thus require an inactive server to be started up, merely to obtain or manipulate configuration and similar information. Such startup procedures limit the flexibility of the administrative tools, and require unnecessary consumption of computer resources. This is particularly the case where a client needs to determine configuration information for a large number of servers on the network.
Similarly, network managers use network management tools to determine the state of network resources, such as routers, bridges, printers, file servers, disk drives, workstations and the like. With conventional network management tools, such as tools compliant with the SNMP or CMIP standards, individual managed objects are associated with each network device. The network manager can query and configure networked devices through manipulation of the managed object associated with each device. These managed objects however, are limited to conveying information at the device level, and do not query or manipulate object level information for individual processes, particularly for servers running on workstations and similar processing units. For example, SNMP tools currently do not determine the interfaces implemented by a given server on a particular workstation. Thus, these tools do not provide adequate level of granularity for use by a systems administrator of a client-server system built on a distributed object programming environment.
Additionally, SNMP and CMIP tools require the network device associated with each managed object to be operating and available on the network in order for the managed object to determine and configure the state of the network device. Conventional managed objects are unable to automatically startup their associated network devices, and thus if the network device crashes or its otherwise terminated, the managed object and the SNMP tool is unable to provide information about the network device. This is because the managed objects do not have information about the startup configuration of the network devices, as the managed objects operate on the assumption that the associated network devices are already operating. Thus, these tools would also require the servers to be executing in order for any information to be obtained. Similarly, with low level protocols, like RPC, no information is stored about pathnames, configuration information or the like for servers, again, preventing an RPC agent from starting a networked server, or providing process level information.
In conventional systems where the processes created by an application all reside in a common address space, typical system administrative tools require providing an explicit reference to the host machine and the process or processes for which information is requested. In a distributed object programming environment, however, a client invokes a server through an object reference, without having information as to where the invoked object resides in the system, that is, without specifically knowing the computer where the invoked object is stored or where its running. Rather, the client passes the object reference through an object request broker which locates the server, and passes back any output from the server to the client. To the user, the client and server, and any group of distributed objects, behave transparently as an integrated application, even though the objects may be distributed in various computer systems. One standard for the distributed object programming is the Common Object Request Broker Architecture (CORBA), specified by the Object Management Group. In this environment, conventional system administrative tools are shielded from the actual implementation of the server, and do not have a mechanism for obtaining unified access to the internal structure of a server, particuarly its configuration setup. While such information may be available in various objects in various parts of the environment, such as naming services, and the like, there is no unified object that provides this information access efficiently.
Accordingly, it is desirable to provide a method and system for obtaining and manipulating configuration information about servers on computers in a distributed object programming environment without starting up the servers, and where only an object reference to the server is available to clients.